Pick-off spindle chucking mechanism



Mayl?, 1960 c. E. MILLER 2,937,030k

' PICK-*OFF SPIDLE CHUCKING MECHANISM l Filed sept. 11, 1957 -z'sneets-sneet Il .IUI

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May 17, 1960 c. E. MILLER PICK-OFF SPINDLE cHucxING MECHANISM Filed sept. 11. 1957 2 Sheets-Sheet 2 2,937,030,` l PICK-ors SPINDLE cHUcxrNG MEcHANrsM Y Carroll E. Miller, Windsor, Vt., yassignor to Conel Auto-y matic Machine Company, Inc., Windsor, Vt., a corporation of Vermont Application September 11, 1957, Serial No. 683,356" 10 6 Claims. ((11.279-75) -This application is a continuation, in part, of my coover the work-piece. This chuck is then closed to grip:

the work-piece just before it is cut off from the bar of stock. An object of the present invention is to provide closed-chuck locking mechanism which operates independently of any axial movement of the spindle as a whole to avoid any movement strain which could influence or disturb the chuck position on the work-piece;l y

.united Another object of the invention is to utilize a rotary movement to rotate rghtand left-hand screws so' as to prevent 1 the applied forces from exerting any pressure on the pick-ott spindle which could tend to move,v the chuck relatively to the work-piece. l i j For amore complete understanding of the invention reference'may be had to the following description thereo'f, and to the drawings, of which: 1 1. 1

.Figure 1 is a partial sectional view of an automatic lathe showing the mechanismv embodying the present invention, the section being taken" on' the line 1 1 of Figurez; Y

Figure 2 is a section on the line2 2' of Figurel;

Y Figure 3 vis a sectional view, on alarger scale, o'f. the pick-off 'spindle shownin yFigure '1,'th'es'ection beingtaken on the line 3 3 of Figure 2;

Figure 3a is a fragmentary longitudinal section of the locking portion of the pick-olf spindle shown in Figure 3, but on a larger scale;

Figures 4, 5 and 6 are sections on the lines 4 4, 5 5, and 6 6, respectively, o'f Figure 3, and

Figure 7 is a section on the line 7 7 of Figure 6.Y

The drawings illustrate portions of an automatic multispindle lathe having the usual housing with transverse frame members 211, 212, and 503 having bearings for shafts and spindles as hereinafter described. Two constantly driven shafts 20 and 43 are shown, the former driving a pick-off spindle 30 through a gear train 19, 18, 26, 28, 32. The shaft 43 is driven through a worm 39a and gear 43a connection and, in turn, has a driving co'nnection through gears 58, 59, 60 with a cam cluster generally indicated at 61. This cluster controls the operation of various tools (not shown) which operate onthe work. The shaft 43 also operates other members including a cam holder 63 on which is mounted a cam 63a.

The pick-off spindle 30 comprises a collet tube 501 on an end of which is a collet 134, a chucking tube 131 on an end of which is a chucking head 127 which operates on the collet 134 when the tubes are relatively moved axially, and a locking tube 132 which at o'ne end abuts a split nut 133 adjustably mounted on the collet tube 501.

`v -'ingfcam sleeve 126 slidably tted on a portion kof the chucking tube 131. Thissleeve has an inner circumfer-- ICC an ejector 506 to dislodge a work-piece from the chuck asV hereinafter described.`

-To advance'the pick-off spindle to cover ,and grip a workpiece,one ofthe cams inthe `cluster 61 ro'cks'an arm 167` to advance a rod 199 which is adjustably secured to a bracket 125. pThis bracketlembraces the pick-off spindle which rotates therein, but vrelative axial movement is prevented by two collars 129, xed on the chucking tube 131 on either side of the bracket. Thus, forward movement of the rod 199 results in similar movement o'f the chucking tube.

Mounted at the rearv end of` the collet tube 501 is af bearing carrying a bracket 500 which moves axially with the collet tube but does not revolve. The bracket 500 has a portion slidable on rod 502 the ends of whichv are mounted on the frame member 503 and an outboard snpport 504 respectively. When the spindle is advanced tov co'ver a work-piece, the collet tube 501 goes with the chucking tube 131 until the bracket 500 brings up against a stop collar 505 adjustably secured on therrod 502. Further advance of the chucking tube 131 is relative with respect to the stopped collet tube and results in a closing of the collet on the work-piece. Y According to the invention, means are now operated to lo'ck the chuck in gripping position so that the spindle asl a whole can be shifted without relaxing the grip on the work-piece. To this end the cam 63a operates at the proper moment to rockan arm 120 which has Va rack 122 at the end thereof. YThe rack rotates a pinion 121 which isnsplined'onashaft 123 as' illustrated in Figurel so that it can move axia'llyi The shaft 12,3 hasV two portions which are o'ppositely screw-threaded, one portion being in threaded engagement with the bracket 125, the.

other portion being in threaded` engagement with a fork 124` which engages in a circumferential groove iny a lockential groove withV sloping side walls (Figure 7) to receive a number of balls 128 which are distributed around the collet tube 501 between two' Vchamfered wedge.v

rings 136,?137. vThe ring 136 abuts a shoulder within the chuck tubev131. The ring 137 abuts an end of the close the chuck on the wo'rk, the shaft 123 is rotated as described to move the locking sleeve forward so as to cam the balls 128 radially inward between the wedging rings 136, 137, this being the position illustrated in Figure 1. The split nut 133 has been previously adjusted on the tube 501 so that the wedge rings, balls and tube 132 tightly lock the chuck tube 131 against any movement toward the rear with respect to the collet tube 501. The assembly, however, vcan readily be retracted, the shaft 123 having a sliding co'nnection with the pinion 121.

When the time comes for the release of the work-piece,

' the cam 63a rocks the rack arm 120 in the opposite direction, shifting the locking sleeve toward the rear to bring the groove 135 around the balls 128 so that the latter .can move radially outward to permit retraction o'f the tion sliding on the rod 502 and is adjustably secured by a screw 509 to a slotted member 510 projecting vvfrom thek bracket 500. When the collet 134 moves over a work-v piece, the .latter pushes a sleeve 506 on the inner end 2,937,030 v :Patented May. 1 l`l V Within the spindle is an ejector rod 507 arranged to push i of the rod 567 to compress a spring 511 carried by the rod 507. When the work-piece is later released by the chuck, the spring causes the sleeve 506 to eject the workpiece.

` I claim: n

l. In an automatic lathe, a pick-offrspindle having a collet chuck and two nested tubular members relatively movable axially to close and open said chuck and lock- 5. In a machine tool, a rotatable work-holding spindle i having a chuck and two tubular members relatively moving means carried by said spindle and axially movable asY v a unit therewith, said means including wedge'elements radially movable when said chuck is closed tolock and unlock said members against chuck-opening Yrelative movement. Y Y

2. In an automatic lathe, a pick-off spindle having a collet chuck and two nested tubular members relatively movable axially to close and open said chuck, and locking means carried by said spindle and axially movable as a unit therewith, said means including a rotatable shaft parallel to the spindle axis and mechanism operable by rotation of said shaft when said' chuckY is closed to lock and unlock said members against chuck-opening relative movement.

' 3. In an automatic lathe, a pick-olf spindle having a collet chuck and two nested tubular members relatively movable axially to close and open said chuck, and locking means carried by said spindle and axially movable as a unit therewith, said means comprising opposed spaced shoulders on said members arranged to move away from each other when said membersrrno've relatively to close said chuck, wedging means between said shoulders operable when said chuck is closed to block any movement v of said shoulders toward eachother, said wedging means including two rings with opposed chamfered facesl flaring radially outward, a series of balls between said faces,` a cam sleeve slidable axially to press said balls radially inward between said faces, and automatic means independent of axial movement of said spindle for sliding said sleeve to locking and unlocking positions.

4. Mechanism as in claim 3, said last named means in cluding an arm having a rack at the free end thereof, a pinion meshing with said rack and mounted` for rotation about an axis parallel toy the axis of said spindle, a shaft extending through said pinion and splined thereto to be rotated thereby; a bracket embracing said spindle, means holding said bracket against linear movement relative to said spindle, a fork straddling said cam sleeve and linearly movablev therewith parallel to said spindle, and screw means onsaid shaft operable by rotation of the shaft to move said bracket and for-kV toward and away kfrom each other.

able axially to open and close the chuck, said members having spaced mutually opposed annular shoulders, wedging means between said shoulders for locking said members against chuck-opening movement, said wedging means including elements radially movable outward to release said membersfor chuck-opening relative movement, a sleeve 'surrounding said wedging means and normally preventing outward movement of said elements, said sleeve having an inner circumferential groove, and means for shifting said sleeve axially to bring said grooves into; registryvwith said elements whereby outward movementV of said elements is permitted. Y

6. In a machine tool, a rotatable work-holding spindle having a chuck and outer and inner tubular members relatively axially movable to open and close the chuck, two spaced collars secured on said outer tubular member, a bracket fitted between said collars and surrounding said outer memberpwherebyrsaid spindle is rotatable but not axially movable with respect toV said bracket, a ro'd secured to said bracket and operable to .move the bracket and spindle axially, said tubular members having spaced opposed shoulders thereon, wedging means between said shoulders for locking said members against chuck-opening relative movement, said wedging means including elements movable radially outward to release said member for chuck-opening movement, a sleeve surrounding said wedging means and normally preventing said elements from outward movement, said sleeve having an inner circumferential groove, and means for axially moving said sleeve to bring said groove into registry with said elements vfor limited outward movement of said elements to permit opening o'f the chuck, said sleeve-moving means including a Vmember mounted on said sleeve for axial movement but not 4rotation therewith, and means engaging said bracket and last mentioned member and operable to cause said last mentioned member to move axially relatively to said bracket.

Y Referencesl Cited in the file of this patent UNITED STATES PATENTS i 1,807,265v walker May 26, 1931 2,459,649 Jahrl Ian. 18, 1949 2,835,497 Suhner May 20, 1958 l FORI-:rois PATENTS f 465,428 Canadaf.- May 23,- 195o 

